Led lamp for producing biologically-adjusted light including a cyan led

ABSTRACT

An LED lamp comprising a housing, a drive circuit configured to electrically couple to a power source, and an LED package that is electrically coupled to and driven by the drive circuit. The LED package comprises a first LED configured to emit light having a peak intensity of about 450 nm, a second LED configured to emit light having a peak intensity within the range from 475 nm to 495 nm, and a color conversion material configured to perform a Stokes shift on light having a wavelength within the range from 440 nm to 460 nm.

RELATED APPLICATIONS

This application is a continuation-in-part and claims the benefit under35 U.S.C. §120 of U.S. patent application Ser. No. 14/514,010 titledThree-Channel Tuned LED Lamp for Producing Biologically-Adjusted Lightfiled Oct. 14, 2014 (Attorney Docket No. 588.00069), which in turn is acontinuation-in-part of U.S. patent application Ser. No. 14/165,198, nowU.S. Pat. No. 8,941,329 titled Tunable LED Lamp for ProducingBiologically-Adjusted Light filed Jan. 27, 2014 (Attorney Docket No.588.00059), which is in turn a continuation of U.S. patent applicationSer. No. 13/311,300, now U.S. Pat. No. 8,686,641, titled Tunable LEDLamp for Producing Biologically-Adjusted Light filed Dec. 5, 2011(Attorney Docket No. 588.00013), the contents of each of which areincorporated in their entirety herein by reference except to the extentdisclosure therein is inconsistent with disclosure herein.

FIELD OF THE INVENTION

The present invention relates to systems and methods of providing alighting device to emit light configured to have various biologicaleffects on an observer.

BACKGROUND OF THE INVENTION

This background information is provided to reveal information believedby the applicant to be of possible relevance to the present invention.No admission is necessarily intended, nor should be construed, that anyof the preceding information constitutes prior art against the presentinvention.

Melatonin is a hormone secreted at night by the pineal gland. Melatoninregulates sleep patterns and helps to maintain the body's circadianrhythm. The suppression of melatonin contributes to sleep disorders,disturbs the circadian rhythm, and may also contribute to conditionssuch as hypertension, heart disease, diabetes, and/or cancer. Bluelight, and the blue light component of polychromatic light, have beenshown to suppress the secretion of melatonin. Moreover, melatoninsuppression has been shown to be wavelength dependent, and peak atwavelengths between about 420 nm and about 480 nm. As such, individualswho suffer from sleep disorders, or circadian rhythm disruptions,continue to aggravate their conditions when using polychromatic lightsources that have a blue light (420 nm-480 nm) component.

Curve A of FIG. 1 illustrates the action spectrum for melatoninsuppression. As shown by Curve A, a predicted maximum suppression isexperienced at wavelengths around about 460 nm. In other words, a lightsource having a spectral component between about 420 nm and about 480 nmis expected to cause melatonin suppression. FIG. 1 also illustrates thelight spectra of conventional light sources. Curve B, for example, showsthe light spectrum of an incandescent light source. As evidenced byCurve B, incandescent light sources cause low amounts of melatoninsuppression because incandescent light sources lack a predominant bluecomponent. Curve C, illustrating the light spectrum of a fluorescentlight source, shows a predominant blue component. As such, fluorescentlight sources are predicted to cause more melatonin suppression thanincandescent light sources. Curve D, illustrating the light spectrum ofa white light-emitting diode (LED) light source, shows a greater amountof blue component light than the fluorescent or incandescent lightsources. As such, white LED light sources are predicted to cause moremelatonin suppression than fluorescent or incandescent light sources.

As the once ubiquitous incandescent light bulb is replaced byfluorescent light sources (e.g., compact-fluorescent light bulbs) andwhite LED light sources, more individuals may begin to suffer from sleepdisorders, circadian rhythm disorders, and other biological systemdisruptions. One solution may be to simply filter out all of the bluecomponent (420 nm-480 nm) of a light source. However, such a simplisticapproach would create a light source with unacceptable color renderingproperties, and would negatively affect a user's photopic response.

SUMMARY OF THE INVENTION

With the foregoing in mind, embodiments of the present invention arerelated to light sources and, more specifically, to a light-emittingdiode (LED) lamp for producing a biologically-adjusted light.

Provided herein are embodiments of an LED lamp comprising a housing, adrive circuit configured to electrically couple to a power source, andan LED package that is electrically coupled to and driven by the drivecircuit. The LED package may comprise a first LED configured to emitlight having a peak intensity of about 450 nm, a second LED configuredto emit light having a peak intensity within the range from 475 nm to490 nm, and a color conversion material configured to perform a Stokesshift on light having a wavelength within the range from 440 nm to 460nm. The light emitted by the LED lamp may be configured to suppressmelatonin secretion in an observer.

In some embodiments, the LED lamp may not comprise, and may specificallyexclude, an LED configured to emit light having a wavelength greaterthan 600 nm. Furthermore, the LED lamp may not comprise, and mayspecifically exclude, a color conversion material configured to emitlight having a wavelength greater than 600 nm.

In some embodiments, the LED package may consist of a first LEDconfigured to emit light having a peak intensity of about 450 nm, asecond LED configured to emit light having a peak intensity within therange from 475 nm to 490 nm, and a color conversion material configuredto perform a Stokes shift on light having a wavelength within the rangefrom 440 nm to 460 nm.

In some embodiments, the LED lamp may comprise a plurality of LEDpackages. Furthermore, the plurality of LED packages may consist of LEDpackages comprising a first LED configured to emit light having a peakintensity of about 450 nm, a second LED configured to emit light havinga peak intensity within the range from 475 nm to 490 nm, and a colorconversion material configured to perform a Stokes shift on light havinga wavelength within the range from 440 nm to 460 nm. Additionally, theplurality of LED packages may consist of LED packages consisting of afirst LED configured to emit light having a peak intensity of about 450nm, a second LED configured to emit light having a peak intensity withinthe range from 475 nm to 490 nm, and a color conversion materialconfigured to perform a Stokes shift on light having a wavelength withinthe range from 440 nm to 460 nm.

In some embodiments, light emitted by the LED lamp may have a CRI of atleast 90. Additionally, light emitted by the LED lamp may have a CCT ofless than 5000K. Furthermore, light emitted by the LED lamp may have anR9 value of at least 90. Additionally, light emitted by the LED lamp mayhave a CCT of less than 4000K.

In some embodiments, the color conversion material may be configured toemit light having a peak intensity within the range from 500 nm to 560nm. The LED lamp may further comprise an optic carried by the housingand positioned in optical communication with the LED package.Furthermore, the housing may be configured to facilitate the attachmentof the LED lamp to a troffer light fixture. In some embodiments, thehousing itself may be a troffer fixture that may be installed in aceiling, such as a drop ceiling.

In some embodiments, the LED lamp may further comprise an output selectcontroller electrically coupled to the drive circuit to program thedrive circuit to drive the LED package in one of a plurality of lightoutput configurations, wherein the plurality of light outputconfigurations includes a general lighting configuration and aphase-shift configuration. The light output in the phase-shiftconfiguration may have a peak intensity within the range from 475 nm to490 nm that is greater than a peak intensity within the range from 475nm to 490 nm of the light output in the general lighting configuration

Various aspects and alternative embodiments are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the light spectra of conventional light sources incomparison to a predicted melatonin suppression action spectrum forpolychromatic light.

FIG. 2 is a perspective view of an LED lamp in accordance with oneembodiment presented herein.

FIG. 3 is an exploded view of the LED lamp of FIG. 2.

FIG. 4 is an exploded view of a portion of the LED lamp of FIG. 2.

FIG. 5 is an exploded view of a portion of the LED lamp of FIG. 2.

FIG. 6 is an exploded view of a portion of the LED lamp of FIG. 2.

FIG. 7 is an exploded view of a portion of the LED lamp of FIG. 2.

FIG. 8 is a schematic process diagram of an LED lamp in accordance withthe present invention.

FIG. 9 illustrates a relative radiant power curve for a mint LED dieused in one embodiment presented herein.

FIGS. 10A and 10B present color bin data for a mint LED die used III oneembodiment presented herein.

FIG. 11 shows relative spectral power distributions for red, cyan, andblue LED dies that are used in one embodiment presented.

FIG. 12 shows a power spectral distribution of an LED lamp III apre-sleep configuration, in accordance with another embodimentpresented.

FIG. 13 shows a power spectral distribution of an LED lamp in aphase-shift configuration, in accordance with one embodiment presented.

FIG. 14 shows a power spectral distribution of an LED lamp in a generallighting configuration, in accordance with one embodiment presented.

FIG. 15 is an exploded view of an LED lamp in accordance with anotherembodiment presented.

FIG. 16 shows an alternative power spectral distribution for an LED lampin a pre-sleep configuration.

FIG. 17 shows an alternative power spectral distribution for an LED lampin a phase-shift configuration.

FIG. 18 shows an alternative power spectral distribution for an LED lampin a general lighting configuration.

FIG. 19 shows a power spectral distribution of an LED lamp in accordancewith one embodiment presented.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Melatonin is a hormone secreted at night by the pineal gland. Melatoninregulates sleep patterns and helps to maintain the body's circadianrhythm. The suppression of melatonin contributes to sleep disorders,disturbs the circadian rhythm, and may also contribute to conditionssuch as hypertension, heart disease, diabetes, and/or cancer. Bluelight, and the blue light component of polychromatic light, have beenshown to suppress the secretion of melatonin. Moreover, melatoninsuppression has been shown to be wavelength dependent, and peak atwavelengths between about 420 nm and about 480 nm. As such, individualswho suffer from sleep disorders, or circadian rhythm disruptions,continue to aggravate their conditions when using polychromatic lightsources that have a blue light (420 nm-480 nm) component.

Curve A of FIG. 1 illustrates the action spectrum for melatoninsuppression. As shown by Curve A, a predicted maximum suppression isexperienced at wavelengths around about 460 nm. In other words, a lightsource having a spectral component between about 420 nm and about 480 nmis expected to cause melatonin suppression. FIG. 1 also illustrates thelight spectra of conventional light sources. Curve B, for example, showsthe light spectrum of an incandescent light source. As evidenced byCurve B, incandescent light sources cause low amounts of melatoninsuppression because incandescent light sources lack a predominant bluecomponent. Curve C, illustrating the light spectrum of a fluorescentlight source, shows a predominant blue component. As such, fluorescentlight sources are predicted to cause more melatonin suppression thanincandescent light sources. Curve D, illustrating the light spectrum ofa white light-emitting diode (LED) light source, shows a greater amountof blue component light than the fluorescent or incandescent lightsources. As such, white LED light sources are predicted to cause moremelatonin suppression than fluorescent or incandescent light sources.

As the once ubiquitous incandescent light bulb is replaced byfluorescent light sources (e.g., compact-fluorescent light bulbs) andwhite LED light sources, more individuals may begin to suffer from sleepdisorders, circadian rhythm disorders, and other biological systemdisruptions. One solution may be to simply filter out all of the bluecomponent (420 nm-480 nm) of a light source. However, such a simplisticapproach would create a light source with unacceptable color renderingproperties, and would negatively affect a user's photopic response.

On the other hand, because exposure to light generally, and blue lightin particular, can reduce the level of drowsiness by suppressing thesecretion of melatonin, exposure to light can be employed to maintainalertness when needed. Additionally, exposure to enhanced the blue lightintensities can help to reset, or shift, the phase of the circadianrhythm of an individual. As such, phase-shifting can be useful in avariety of situations when resetting an individual's internal body clockis desired. Examples include: avoiding jetlagged after inter-continentaltravel, or maintaining alertness for shift-workers who are engaged innighttime work. Although varying the intensity of the blue spectralcomponent of a light source can be achieved through simple filtering,such filtering results in a non-optimal lighting environment.

As such, presenting herein is an LED lamp with commercially acceptablecolor rendering properties, which can be tuned to produce varying lightoutputs. In one embodiment, the light output produces minimal melatoninsuppression, and thus has a minimal effect on natural sleep patterns andother biological systems. The LED lamp may also be tuned to generatedifferent levels of blue light, appropriate for the given circumstance,while maintaining good light quality and a high CRI in each case. TheLED lamp may also be configured to “self-tune” itself to generate theappropriate light output spectrum, depending on factors such as thelamp's location, use, ambient environment, etc.

The light output states/configurations achievable by the LED lampspresented include: a pre-sleep configuration, a phase-shiftconfiguration, and a general lighting configuration. In the pre-sleepconfiguration, the lamp generates a reduced level of blue light in orderto provide an adequate working environment while significantly lesseningthe suppression of melatonin. The spectrum of light produced by the lampin the pre-sleep configuration provides an environment appropriate forpreparing for sleep while still maintaining light quality. In thephase-shifting configuration, the lamp generates an increased level ofblue light, thereby greatly diminishing melatonin production. Thespectrum of light produced by the lamp in this phase-shiftingconfiguration provides an environment for shifting the phase of anindividual's circadian rhythm or internal body clock. In the generallighting configuration, the lamp generates a normal level blue light,consistent with a typical light spectrum (e.g., daylight). In allstates, however, the lamp maintains high visual qualities and CRI, inorder to provide an adequate working environment.

In one embodiment, the ability to tune, or adjust, the light output isprovided by employing a specific combination of LED dies of differentcolors, and driving the LED dies at various currents to achieve thedesired light output. In one embodiment, the LED lamp employs acombination of red, blue, cyan, and mint LED dies, such that thecombination of dies produces a desired light output, while maintaininghigh quality light and high CRI.

The following detailed description of the figures refers to theaccompanying drawings that illustrate an exemplary embodiment of atunable LED lamp for producing a biologically-adjusted light output.Other embodiments are possible. Modifications may be made to theembodiment described herein without departing from the spirit and scopeof the present invention. Therefore, the following detailed descriptionis not meant to be limiting.

FIG. 2 is a perspective view of an LED lamp (or bulb) 100 in accordancewith one embodiment presented herein. In general, LED lamp 100 isappropriately designed to produce biologically-adjusted light, whilestill maintaining a commercially acceptable color temperature andcommercially acceptable color rending properties.

The term “biologically-adjusted light” is intended to mean “a light thathas been modified to manage biological effects on a user.” The term“biological effects” is intended to mean “any impact or change a lightsource has to a naturally occurring function or process.” Biologicaleffects, for example, may include hormone secretion or suppression(e.g., melatonin suppression), changes to cellular function, stimulationor disruption of natural processes, cellular mutations or manipulations,etc.

As shown in FIG. 2, LED lamp 100 includes a base 110, a heat sink 120,and an optic 130. As will be described below, LED lamp 100 furtherincludes one or more LED chips and dedicated circuitry

Base 110 is preferably an Edison-type screw-in shell. Base 110 ispreferably formed of an electrically conductive material such asaluminum. In alternative embodiments, base 110 may be formed of otherelectrically conductive materials such as silver, copper, gold,conductive alloys, etc. Internal electrical leads (not shown) areattached to base 110 to serve as contacts for a standard light socket(not shown). Additionally, base 110 may be adapted to be any type oflamp base known in the art, including, but not limited to, bayonet,bi-post, bi-pin and wedge bases.

As known in the art, the durability of an LED chip is usually affectedby temperature. As such, heat sink 120, and structures equivalentthereto, serves as means for dissipating heat away from one or more ofthe LED chips within LED lamp 100. In FIG. 2, heat sink 120 includesfins to increase the surface area of the heat sink. Alternatively, heatsink 120 may be formed of any configuration, size, or shape, with thegeneral intention of drawings heat away from the LED chips within LEDlamp 100. Heat sink 120 is preferably formed of a thermally conductivematerial such as aluminum, copper, steel, etc.

Optic 130 is provided to surround the LED chips within LED lamp 100. Asused herein, the terms “surround” or “surrounding” are intended to meanpartially or fully encapsulating. In other words, optic 130 surroundsthe LED chips by partially or fully covering one or more LED chips suchthat light produced by one or more LED chips is transmitted throughoptic 130. In the embodiment shown, optic 130 takes a globular shape.Optic 130, however, may be formed of alternative forms, shapes, orsizes. In one embodiment, optic 130 serves as an optic diffusing elementby incorporating diffusing technology, such as described in U.S. Pat.No. 7,319,293 (which is incorporated herein by reference in itsentirety). In such an embodiment, optic 130, and structures equivalentthereto, serves as a means for defusing light from the LED chips. Inalternative embodiments, optic 130 may be formed of a light diffusiveplastic, may include a light diffusive coating, or may having diffusiveparticles attached or embedded therein.

In one embodiment, optic 130 includes a color filter applied thereto.The color filter may be on the interior or exterior surface of optic130. The color filter is used to modify the light output from one ormore of the LED chips. In one embodiment, the color filter is a ROSCOLUX#4530 CALCOLOR 30 YELLOW. In alternative embodiments, the color filtermay be configured to have a total transmission of about 75%, a thicknessof about 50 microns, and/or may be formed of a deep-dyed polyester filmon a polyethylene terephthalate (PET) substrate.

In yet another embodiment, the color filter may be configured to havetransmission percentages within +/−10%, at one or more wavelengths, inaccordance with the following table:

Wavelength Transmission (%) 360 380 400 66 64 49 30 22 420 440

FIG. 3 is an exploded view of LED lamp 100, illustrating internalcomponents of the lamp. FIGS. 4-7 are exploded views of portions of LEDlamp 100. FIGS. 3-7 also serve to illustrate how to assemble LED lamp100. As shown, in addition to the components described above, LED lamp100 also includes at least a housing 115, a printed circuit board (PCB)117, one or more LED chips 200, a holder 125, spring wire connectors127, and screws 129.

As described in more detail with reference to FIG. 8, PCB 117 includesdedicated circuitry, such as power supply 450, driver circuit 440, andoutput-select controller 445. The circuitry on PCB 117 and equivalentsthereof serves as a means for driving the LED chips 200 (or individualLED dies) to produce a biologically-adjusted light output.

As used herein, the term “LED chip(s)” is meant to broadly include LEDdie(s), with or without packaging and reflectors, that may or may not betreated (e.g., with applied phosphors). In the embodiment shown,however, each LED chip 200 includes a plurality of LED dies. In oneembodiment, LED chips 200 include an LED package comprising a pluralityof LED dies, with at least two different colors, driven at varyingcurrents to produce the desired light output and spectral powerdensities. Preferably, each LED chip 200 includes two red LED dies,three cyan LED dies, four mint LED dies, and three blue LED dies. FIG. 9illustrates a relative radiant power curve for a mint LED die used inone embodiment presented herein. FIGS. 10A and 10B present color bindata for a mint LED die used in one embodiment presented herein. FIG. 11shows relative spectral power distributions for red (or alternativelyred-orange), cyan, and (two alternative) blue LED dies that are used inone embodiment presented (with alternative equivalent LED dies alsobeing within the scope of the present invention). With this uniquecombinations of dies, together with the means for driving the LED chips,each of the above mentioned bio-effective states/configurations (e.g.,pre-sleep, phase-shifting, and/or general lighting) can be obtained withgood color rendering properties.

In one embodiment the tunable LED lamp operates in the pre-sleepconfiguration such that the radiant power emitted by the dies is in aratio of: about 1 watt of radiant power generated by the mint LED dies,to about 0.5 watts of radiant power generated by the red-orange LEDdies, to about 0.1 watts of radiant power generated by the cyan LEDdies. In this embodiment the tunable LED lamp operates in the generallighting configuration such that the radiant power emitted by the diesis in a ratio about 1 watt of radiant power generated by the mint LEDdies, to about 0.3 watts of radiant power generated by the red-orangeLED dies, to about 0.4 watts of radiant power generated by the cyan LEDdies, to about 0.2 watts of radiant power generated by the blue LEDdies. In this embodiment, the tunable LED lamp operates in thephase-shift configuration such that the radiant power emitted by thedies is in a ratio of about 1 watt of radiant power generated by themint LED dies, to about 0.1 watts of radiant power generated by thered-orange LED dies, to about 0.2 watts of radiant power generated bythe cyan LED dies, to about 0.4 watts of radiant power generated by theblue LED dies.

In another embodiment, the tunable LED lamp operates in the pre-sleepconfiguration such that the radiant power emitted by the dies is in aratio of: about 1 watt of radiant power generated by the mint LED dies,to about 0.8 watts of radiant power generated by the red-orange LEDdies, to about 0.3 watts of radiant power generated by the cyan LEDdies. In this embodiment, the tunable LED lamp operates in the generallighting configuration such that the radiant power emitted by the diesis in a ratio about 1 watt of radiant power generated by the mint LEDdies, to about 0.2 watts of radiant power generated by the red-orangeLED dies, to about 0.2 watts of radiant power generated by the blue LEDdies. In this embodiment, the tunable LED lamp operates in thephase-shift configuration such that the radiant power emitted by thedies is in a ratio of about 1 watt of radiant power generated by themint LED dies, to about 0.1 watts of watts of radiant power generated bythe red-orange LED dies, to about 0.5 watts of radiant power generatedby the blue LED dies.

For example, to achieve a pre-sleep configuration, driver circuit 440may be configured to drive the plurality of LED dies such that a blueoutput intensity level, in a visible spectral output range of betweenabout 380 nm and about 485 nm, is less than about 10% of a relativespectral power of any other peaks in the visible spectral output aboveabout 485 nm. In one embodiment, driver circuit 440 drives the pluralityof LED dies such that about 150 mA of current is delivered to four mintLED dies; about 360 mA of current is delivered to two red LED dies; andabout 40 mA of current is delivered to three cyan LED dies. In anotherembodiment, wherein a color filter as described above is employed, thepre-sleep configuration is achieved by configuring driver circuit 440 todeliver about 510MA of current to 4 mint LED dies.

To achieve a phase-shift configuration, driver circuit 440 may beconfigured to drive the plurality of LED dies such that a blue outputintensity level, in a visible spectral output range of between about 455nm and about 485 nm, is greater than about 125% (or greater than about150%; or greater than about 200%) of a relative spectral power of anyother peaks in the visible spectral output above about 485 nm. The colorrendering index in the phase-shift configuration may be greater than 80.In one embodiment, driver circuit 440 drives the plurality of LED diessuch that about 510 mA of current is delivered to the mint LED dies;about 180 mA of current is delivered to the red LED dies; about 40 mA ofcurrent is delivered to the cyan LED dies; and about 100 mA of currentis delivered to the blue LED dies.

To achieve a general lighting configuration, driver circuit 440 may beconfigured to drive the plurality of LED dies such that a blue outputintensity level, in a visible spectral output range of between about 380nm and about 485 nm, is between about 100% to about 20% of a relativespectral power of any other peaks in the visible spectral output aboveabout 485 nm. The color rendering index in the general lightingconfiguration may be greater than 85. In one embodiment, driver circuit440 drives the plurality of LED dies such that about 450 mA of currentis delivered to the mint LED dies; about 230 mA of current is deliveredto the red LED dies; about 110 mA of current is delivered to the cyanLED dies; and about 60 mA of current is delivered to the blue LED dies.

In one embodiment, driver circuit 440 is configured to drive LED chips200 with a ripple current at frequencies greater than 200 Hz. A ripplecurrent at frequencies above 200 Hz is chosen to avoid biologicaleffects that may be caused by ripple currents at frequencies below 200Hz. For example, studies have shown that some individuals are sensitiveto light flicker below 200 Hz, and in some instances experienceaggravated headaches, seizures, etc.

As shown in FIG. 4, base 110 is glued or crimped onto housing 115. PCB117 is mounted within housing 115. Insulation and/or potting compound(not shown) may be used to secure PCB 117 within housing 115. Electricalleads on PCB 117 are coupled to base 110 to form the electrical inputleads of LED lamp 100.

In some embodiments, base 110 may be adapted to facilitate the operationof the LED lamp based upon receiving an electrical signal from a lightsocket that base 110 may be attached to. For example, base 110 may beadapted to receive electrical signals from the socket of a three-waylamp, as is known in the art. Furthermore, driver circuit 440 maysimilarly be adapted to receive electrical signals from base 110 in sucha fashion so as to use the electrical signals from the three-way lamp asan indication of which emitting configuration is to be emitted. Themodes of operation of a three-way lamp are known in the art. Base 110and driver circuit 440 may be adapted to cause the emission of thephase-shift configuration upon receiving a first electrical signal fromthe socket of a three-way lamp, the general illumination configurationupon receiving a second electrical signal from the three-way lamp, andthe pre-sleep configuration upon receiving a third electrical signalfrom the three-way lamp.

More specifically, as is known in the art, base 110 may include a firstterminal (not shown) and a second terminal (not shown), the firstterminal being configured to electrically couple to a low-wattagecontact of a three-way fixture, and the second terminal being configuredto electrically couple to a medium-wattage contact of a three-wayfixture. Driver circuit 440 may be positioned in electricalcommunication with each of the first and second terminals of base 110.When base 110 receives an electric signal at the first terminal, but notat the second terminal, the driver circuit 440 may detect such and maycause the emission of light according to one of the phase-shiftconfiguration, the general illumination configuration, and the pre-sleepconfiguration. When base 110 receives an electrical signal at the secondterminal, but not at the first terminal, the driver circuit 440 maydetect such and may cause the emission of light according to one of thephase-shift configuration, the general illumination configuration, andthe pre-sleep configuration, but not the same configuration as when anelectrical signal was detected at the first terminal and not the second.Finally, base 110 receives an electrical signal at both the firstterminal and the second terminal, driver circuit 440 may detect such andmay cause the emission of light according to one of the phase-shiftconfiguration, the general illumination configuration, and the pre-sleepconfiguration, but not the same configuration as is emitted when anelectrical signal is detected at only one of the first or secondterminals of base 110.

Furthermore, in some embodiments, the driver circuit 440 may beconfigured to cause the emission of light according to any of theconfigurations as described hereinabove based upon the waveform of anelectrical signal received by base 110 and detected by driver circuit440. For example, in some embodiments, driver circuit 440 may beconfigured to cause the emission of light that is responsive to a TRIACsignal. A TRIAC signal is a method of manipulating the waveform of an ACsignal that selectively “chops” the waveform such that only certainperiods of the waveform within an angular range are transmitted to anelectrical device, and is used in lighting.

Driver circuit 440 may be configured to cause the emission of lightaccording to one of the various configurations of light responsive tovarying ranges of TRIAC signals. A range of a TRIAC signal may beconsidered as a portion of a continuous, unaltered AC signal. A firstTRIAG signal range may be a range from greater than about 0% to about33% of an AC signal. This range may correspond to a percentage of thetotal angular measurement of a single cycle of the AC signal.Accordingly, where the single cycle of the AC signal is approximately 2πradians, the first range may be from greater than about 0 to about 0.67πradians. It is contemplated that angular measurement of the TRIAC signalis only one method of defining a range of a characteristic of the TRIACsignal. Other characteristics include, but are not limited to, phaseangle, voltage, RMS voltage, and any other characteristic of an electricsignal. Accordingly, the driver circuit 440 may include circuitrynecessary to determine any of the phase angle, voltage, and RMS voltageof a received signal. The driver circuit 440 may be configured to detectthe TRIAC signal and determine it falls within this range, and mayfurther be configured to cause the emission of light according to one ofthe phase-shift configuration, the general illumination configuration,and the pre-sleep configuration. A second TRIAC signal range may be fromabout 33% to about 67% of an AC signal, which may correspond to a rangefrom about 0.67π to about 1.33π radians. The driver circuit 440 may beconfigured to detect the TRIAC signal and determine it falls within thisrange, and may further be configured to cause the emission of lightaccording to one of the phase-shift configuration, the generalillumination configuration, and the pre-sleep configuration, but not theconfiguration that was emitted when the driver circuit determined theTRIAC signal was within the first TRIAC signal range. A third TRIACsignal range may be from about 67% to about 100% of an AC signal, whichmay correspond to a range from about 1.33π to about 2π radians. Thedriver circuit 440 may be configured to detect the TRIAC signal anddetermine it falls within this range, and may further be configured tocause the emission of light according to one of the phase-shiftconfiguration, the general illumination configuration, and the pre-sleepconfiguration, but not the configuration that was emitted when thedriver circuit determined the TRIAC signal was within either of thefirst TRIAC signal range or the second TRIAC signal range.

In another embodiment, a first TRIAC signal range may be from about 0%to about 25% of an AC signal, corresponding to within a range from about0 to about 0.5π radians. Driver circuit 440 may be configured to detectthe TRIAC signal and determine if it falls within this range, and mayfurther be configured to not emit light. A second TRIAC signal range maybe from about 25% to about 50% of an AC signal, corresponding to withina range from about 0.5π to about 1.0π radians. Driver circuit 440 may beconfigured to detect the TRIAC signal and determine if it falls withinthis range, and may further be configured to cause the emission of lightaccording to one of the phase-shift configuration, the generalillumination configuration, and the pre-sleep configuration. A thirdTRIAC signal range may be from about 50% to about 75% of an AC signal,corresponding to within a range from about 1.0π to about 1.5π radians.Driver circuit 440 may be configured to detect the TRIAC signal anddetermine if it falls within this range, and may further be configuredto cause the emission of light according to one of the phase-shiftconfiguration, the general illumination configuration, and the pre-sleepconfiguration, but not the configuration that was emitted when thedriver circuit determined the TRIAC signal was within the second TRIACsignal range. A fourth TRIAC signal range may be from about 75% to about100% of an AC signal, corresponding to a range from about 1.5π to about2.0 radians. Driver circuit 440 may be configured to detect the TRIACsignal and determine if it falls within this range, and may further beconfigured to cause the emission of light according to one of thephase-shift configuration, the general illumination configuration, andthe pre-sleep configuration, but not the configuration that was emittedwhen the driver circuit determined the TRIAC signal was within either ofthe second or third TRIAC signal ranges.

In order to enable the operation of an LED lamp 100 that is responsiveto an electrical signal, such as a wireless signal or a TRIAC signal, itmay be necessary to configure the power source for the LED lamp 100 toprovide an electrical signal so as to control the operation of the LEDlamp 100. Accordingly, in some embodiments, where the LED lamp 100 iselectrically coupled to a lighting fixture that is controlled by a wallswitch, or where the LED lamp 100 is directly electrically connected toa wall switch, the invention may further comprise a retrofitwall-mounted switch (not shown). In such embodiments, the retrofitwall-mounted switch may operate substantially as the output selectiondevice and the user input device described herein. The retrofitwall-mounted switch may be configured to replace a standard wall switchfor control of a light fixture, as is known in the art. The retrofitwall-mounted switch may be configured to generate or manipulate a signalso as to control the operation of the LED lamp 100. For example, in someembodiments, the retrofit wall-mounted switch may be configured togenerate a wireless signal that may be received by the LED lamp 100 thatmay result in the operation of the LED lamp 100 as describedhereinabove. Also, in some embodiments, the retrofit wall-mounted switchmay be configured to manipulate a power source to which the retrofitwall-mounted switch is electrically coupled so as to generate a TRIACsignal, to which the LED lamp 100 may operate responsively to asdescribed hereinabove. In such embodiments, the retrofit wall-mountedswitch may be positioned electrically intermediate the power source andthe LED lamp 100.

In some embodiments, base 110 may be configured to be a removablyattachable member of LED lamp 100, defined as an intermediate base. Insome other embodiments, an intermediate base may be included in additionthe base 110. Intermediate base 110 may include structural elements andfeatures facilitating the attachment of intermediate base 110 to a partof LED lamp 100. For example, intermediate base 110 may be adapted tocooperate with a feature or structure of housing 115 so as to removablyattach intermediate base 110 thereto. For example, where intermediatebase 110 is an Edison-type base having threading adapted to conform tostandard threading for such bases, housing 115 may include a threadedsection (not shown) configured to engage with the threads ofintermediate base 110 so as to removable attach with intermediate base110. Furthermore, each of intermediate base 110 and LED lamp 100 mayinclude electrical contacts so as to electrically couple LED lamp 100 tointermediate base 110 when intermediate base 110 is attached. The size,position, and configuration of such electrical contacts may varyaccording to the method of attachment between LED lamp 100 andintermediate base 110.

Additionally, intermediate base 110 may include elements facilitatingthe transitioning of LED chips 200 between the various configurations,i.e. pre-sleep, phase shift, and general illuminating configurations.For example, in some embodiments, intermediate base 110 may include auser input device (not shown) adapted to receive an input from a user.The input from the user may cause intermediate base 110 to interact withat least one of driver circuit 440 and a power circuit of the LED lamp100 so as to cause the LED chips 200 to emit light according to any ofthe configurations recited herein.

In some embodiments, the user input may cause the LED lamp 100 totransition from the present emitting configuration to a selectedemitting configuration, or to cease emitting light. In some embodiments,the user input may cause the LED lamp 100 to progress from one emittingconfiguration to another emitting configuration according to a definedprogression. An example of such a progression may be, from an initialstate of not emitting light, to emitting the phase-shift configuration,to emitting the general illumination configuration, to emitting thepre-sleep configuration, to ceasing illumination. Such a progression isexemplary only, and any combination and permutation of the variousemitting configurations are contemplated and included within the scopeof the invention. The base 110 may include circuitry necessary toreceive the input from the user and to communicate electrically with thevarious elements of the LED lamp 100 to achieve such function.

In some embodiments, the user input device may be a device that isphysically accessible by a user when the base 110 is attached to the LEDlamp 100 and when the LED lamp 100 is installed in a lighting fixture.For example, the user input device may be a lamp turn knob operativelyconnected to circuitry comprised by the base 110 to affect thetransitioning described hereinabove. A lamp turn knob is an exemplaryembodiment only, and any other structure or device capable of receivingan input from a user based on electrical and/or mechanical manipulationor operation by the user is contemplated and included within the scopeof the invention. In some embodiments, the user input device may be anelectronic communication device including a wireless communicationdevice configured to receive a wireless signal from the user as theinput. Such user input devices may be adapted to receive a user input inthe form of an infrared signal, a visible light communication (VLC)signal, radio signal, such as Wi-Fi, Bluetooth, Zigbee, cellular datasignals, Near Field Communication (NFC) signal, and any other wirelesscommunication standard or method known in the art. Additionally, in someembodiments, the user input device may be adapted to receive anelectronic signal from the user via a wired connection, including, butnot limited to, Ethernet, universal serial bus (USB), and the like.Furthermore, where the user input device is adapted to establish anEthernet connection, the user input device may be adapted to receivepower from the Ethernet connection, conforming to Power-over-Ethernet(PoE) standards. In such embodiments, the power received by the userinput device may provide power to the LED lamp 100 enabling itsoperation.

In some embodiments, it is contemplated that any of the lighting devicesas described herein may be integrally formed with a lighting fixture,where the LED lamp 100 is not removably attachable to the lightingfixture. More specifically, in some embodiments, those aspects of thelighting devices described herein that are included to permit theattachability of the lighting device to a separately-produced lightingfixture may be excluded, and those aspects directed to the function ofemitting light according to the various lighting configurations asdescribed herein may be included. For example, in the presentembodiment, the base 110 may be excluded, and the driver circuit 440 maybe directly electrically coupled to an external power source or to anelectrical conduit thereto. Furthermore, the geometric configuration ofoptic 130, heat sink 120, LED chips 200, and all other elements of theLED lamp 100 may be adapted to facilitate a desired configuration of anintegrally-formed lighting fixture.

As shown in FIG. 5, heat sink 120 is disposed about housing 115. Asshown in FIG. 6, two LED chips 200 are mounted onto a support surface(or directly to heat sink 120), and maintained in place by holder 125.While two LED chips 200 are shown, alternative embodiments may includeany number of LED chips (i.e., one or more), or any number of LED diesindividually mounted. Screws 129 are used to secure holder 125 to heatsink 120. Screws 129 may be any screws known in the art. Spring wireconnectors 127 are used to connect LED chips 200 to the driver circuit440 on PCB 117. In an alternative embodiment, LED chips 200 (with orwithout packaging) may be attached directly to heat sink 120 without theuse of holder 125, screws 129, or connectors 127. As shown in FIG. 7,optic 130 is then mounted on and attached to heat sink 120.

FIG. 8 is a schematic process diagram of an LED lamp in accordance withthe present invention. FIG. 8 also serves a depiction of the functionalcomponents mounted on PCB 117, or otherwise associated with LED lamp100. In practice, a power supply 450 is used to provide power to drivercircuit 440. Power supply 450 may, for example, convert AC power to DCpower, for driving the LED dies. Driver circuit 440 receives power inputfrom power supply 450, and directional input from output-selectcontroller 445. In turn, driver circuit 440 provides the appropriatecurrent supply to drive the LED dies in accordance with the desiredspectral output. Controller 445 therefore serves to control the drivingof LEDs 200, and may control light output based on factors such as: timeof day, ambient light, real time input, temperature, optical output,location of lamp, etc.

Variations in temperature during operation can cause a spectral shift ofindividual dies. In an embodiment, a photo-sensor 860 is included tomonitor the light output of the LEDs 200 to insure consistency anduniformity. Monitoring the output of LEDs 200 allows for real timefeedback and control of each die to maintain the desired outputspectrum. Photo-sensor 860 may also be used to identify the ambientlight conditions. Photo-sensor 860 thus provides an input to controller445.

In another embodiment, a thermal sensor 855 is used to measure thetemperature of the LED dies and/or board supporting the LED dies.Because the light output of the dies is a known function of temperature,the measured temperature can be used to determine the light output ofeach die. Thermal sensor 855 may also be used to measure the ambienttemperature conditions. Thermal sensor 855 thus provides another inputto controller 445.

In another embodiment, a GPS chip 870 and/or clock 875 is included andinterfaced with controller 445. Because lamps are shipped around theworld to their end location, the ability to determine theexpected/actual ambient light, daily light cycle, and seasonal lightcycle variations is important in any lamp that may generate light tostimulate or alter circadian rhythms. GPS chip 870 and/or clock 875provide inputs into controller 445 such that the time of day,seasonality, and other factors can be taken into account by controller445 to control the lamp output accordingly. For example, by knowing thetime of day based on location, the pre-sleep spectrum of the lamp can begenerated during the later hours of the day.

In still another embodiment, a user-interface 865 is provided to allow auser to select the desired configuration. User-interface 865 may be inthe form of a knob, switch, digital input, or equivalent means. As such,user-interface 865 provides an additional input to controller 445.

In one embodiment, the pre-sleep configuration spectrum includes aportion of the spectrum that is reduced (e.g., notched/troughed) inintensity. This trough is centered at about 470 nm (or alternativelybetween about 470-480 nm, between about 460-480 nm, between about470-490 nm, or between about 460-490 nm). Such wavelength ranges may bethe most important contributor to, and most effective at, suppressingmelatonin. Thus minimizing exposure in such wavelength bands duringpre-sleep phase will be efficacious. In one embodiment, the notching ofthe pre-sleep spectrum is obtained using a phosphor-coated mint LEDhaving a specific output spectrum to accomplish the notch in thepre-sleep spectrum. The mint LED itself may include a notch/trough witha minimum in the 470-480 nm (or 460-490 nm range), and may becharacterized by a maximum intensity in these wavelength ranges as afractional percent of the peak intensity of the mint LED (e.g., themaximum of 470-480 emission is less than about 2.5% of the peakintensity; the max between about 460-490 nm is less than about 5% of thepeak intensity).

With reference again to FIG. 9, illustrated is a relative radiant powercurve for a mint LED die used in one embodiment presented. As usedherein, the terms “mint LED” or “mint LED die” or “mint die” should beconstrued to include any LED source, LED chip, LED die (with or withoutphoto-conversion material on the die), or any equivalent light sourcethat is configured or capable of producing the relative radiant powercurve shown in FIG. 9, or a relative radiant power curve equivalentthereto. Of particular interest to the shown relative radiant powercurve is the spectral “notch” between about 460-490 nm, and morespecifically between at about 470-480 nm. Said spectral notch provides arelative intensity, with respect to the peak intensity, that allows thecombination of LED dies (or equivalent light sources) to achieve theirdesired results (i.e., the desired output configuration). In oneembodiment, the maximum intensity of the mint LED between about 460-490nm is less than about 5% of the peak intensity. In alternativeembodiments the maximum intensity of the mint LED between about 460490nm is less than about 7.5%, or about 10%, or about 15%, or about 20% ofthe peak intensity. Further, in one embodiment, the maximum intensity ofthe mint LED between about 470-480 nm is less than about 2.5% of thepeak intensity. In alternative embodiments, the maximum intensity of themint LED between about 470-480 nm is less than about 3.5%, 5%, 10%, or20% of the peak intensity.

FIGS. 12, 13, and 14 show the power spectral distributions correspondingrespectively to the pre-sleep, phase-shift, and general illuminationconfigurations of the LED lamp in accordance with one embodiment of theinvention. The LED lamp in this embodiment comprises an LED board with aratio of Cyan, Mint, Red, and Royal Blue dies of 3:3:2:1 respectively.The spectral output of the lamp according to each configuration isadjusted by generating radiant fluxes from multiple dies as describedbelow.

FIG. 12 shows a power spectral distribution of an LED lamp III apre-sleep configuration, in accordance with another embodimentpresented. The pre-sleep configuration shown in FIG. 13 is produced byan array of LED dies in the 3:3:2:1 ratio, driven as follows: (1) threecyan LEDs driven at 7.65V, 66 mA, 0.16679 radiant flux; (2) three mintLEDs driven parallel at II.13V, 95ImA, I.8774 radiant flux; (3) twored-orange LEDs driven at 4.375V, 998 mA, 0.96199 radiant flux; and (4)one royal blue LED driven at 2.582V, 30 mA, 0.0038584 radiant flux. Thetotal luminous flux is I.024e+003 1 m. The total radiant flux is3.023ge+000 W. The dominant wavelength is 580.3 nm. The general CRI is87.30. The color temperature is 2871 K. The 1931 Coordinates (2°) are x:0.4649, y: 0.4429. The luminous power per radiant watt is 338 lumens perradiant watt.

FIG. 13 shows a power spectral distribution of an LED lamp in aphase-shift configuration, in accordance with one embodiment presented.The phase-shift configuration shown in FIG. 14 is produced by an arrayof LED dies in the 3:3:2:1 ratio, driven as follows: (1) three cyan LEDsdriven at 8.19V, 235 mA, 0.47233 radiant flux; (2) three mint LEDsdriven parallel at 1I.14V, 950 mA, I.9047 radiant flux; (3) twored-orange LEDs driven at 3.745V, 147 mA, 0.1845 radiant flux; and (4)one royal blue LED driven at 2.802V, 525 mA, 0.69093 radiant flux. Thetotal luminous flux is 9.87ge+002 1 m. The total radiant flux is3.2138e+000 W. The dominant wavelength is 495.6 nm. The peak wavelengthis 449.7 nm. The general CRI is 87.42. The color temperature is 6,599 K.The 1931 Coordinates (2°) are x: 0.3092, y: 0.3406. The luminous powerper radiant watt is 307 lumens per radiant watt.

In an alternative embodiment, in the phase-shift configuration, theintensity levels of blue component in the 455 nm to 485 nm range ispreferably greater than about 125% of the relative spectral power of anyother peaks in the visible light spectrum higher than 485 nm. Inalternative embodiments, the blue component in the 455 nm to 485 nmrange may be is preferably greater than about 150%; or about 175%; orabout 200%; or about 250%; or about 300% of the relative spectral powerof any other peaks in the visible light spectrum higher than 485 nm. Thecolor rendering index is preferably greater than 80. By varying theradiant fluxes of one or more of the dies, for example by varying thecurrent drawn by the dies, the intensity of the blue component relativeto other spectral peaks greater than 485 nm may be adjusted to thedesired level.

FIG. 14 shows a power spectral distribution of an LED lamp in a generallighting configuration, in accordance with one embodiment presented. Thegeneral lighting configuration shown in FIG. 15 is produced by an arrayof LED dies in the 3::3:2:1 ratio, driven as follows: (1) three cyanLEDs driven at 8.22V, 211 mA, 0.44507 radiant flux; (2) three mint LEDsdriven parallel at 10.06V, 499 mA, 1.1499 radiant flux; (3) twored-orange LEDs driven at 3.902V, 254 mA, 0.34343 radiant flux; and (4)one blue LED driven at 2.712V, 190 mA, 0.27280 radiant flux. The totalluminous flux is 7.192e+002 1 m. The total radiant flux is 2.2248e+000W. The dominant wavelength is 566.2 nm. The peak wavelength is 625.9 nm.The general CRI is 93.67. The color temperature is 4897 K. The 1931Coordinates (2°) are x: 0.3516, y: 0.3874. The luminous power perradiant watt is 323 lumens per radiant watt.

In an alternative embodiment, in the general illumination configuration,the intensity levels of blue component in the 380 nm to 485 nm range ispreferably about 100% of the relative spectral power of any other peaksin the visible light spectrum higher than 485 nm. In alternativeembodiments, the intensity levels of blue component in the 380 nm to 485nm range is preferably less than about 100%; or less than about 90%; orless than about 80%; or between about 20% to about 100% of the relativespectral power of any other peaks in the visible light spectrum higherthan 485 nm. The color rendering index is preferably greater than 85.

FIG. 15 is an exploded view of an LED lamp in accordance with anotherembodiment presented. FIG. 15 shows an additional form factor in whichthe present invention may be applied. For example, FIG. 15 shows a lamp1600 having an array of LEDs 1610. The LEDs 1610 may be provided in the3:3:2:1 ratio of cyan:mint:red-orange:blue, as described above.

In another embodiment, the LEDs 1610 may be provided in a 3:3:2:3 ratioof cyan:mint:red:blue, as described above. The LEDs are mounted on asupport frame 1620, which may serve as a heat-sink. LED circuitry 1630is used to drive the LEDs 1610 with appropriate drive currents toachieve two or more output configurations (e.g., pre-sleep, phase-shift,and general lighting configurations). An output-select controller 1640(and associated knob) are provided to allow an end-user to select thedesired output configuration. An optic 1650 is provided in front of theLEDs 1610 to provide diffusive effects. The form factor may be completedby fastening the components with means such as screws and/or nuts andbolts, as shown.

Additional Embodiments

FIGS. 16, 17, and 18 show the power spectral distributions correspondingrespectively to the pre-sleep, phase-shift, and general illuminationconfigurations of the LED lamp in accordance with one embodiment of theinvention. The LED lamp in this embodiment comprises an LED board with aratio of Cyan, Mint, Red, and Blue dies of 3:3:2:3 respectively. Thespectral output of the lamp according to each configuration is adjustedby generating radiant fluxes from multiple dies as described below.

FIG. 16 shows a power spectral distribution of an LED lamp III apre-sleep configuration, in accordance with another embodimentpresented. The pre-sleep configuration shown in FIG. 13 is produced byan array of LED dies in the 3:3:2:3 ratio, driven as follows: (1) threecyan LEDs driven at 7.83V, 91 mA, to generate 0.2048 radiant watts; (2)three mint LEDs driven parallel at 9.42V, 288 mA, 0.6345 radiant watts;(3) two red-orange LEDs driven at 4.077V, 490 mA, 0.5434 radiant watts.The dominant wavelength is 581.4 nm. The general CRI is 71. The colortemperature is 2719 K. The luminous power per radiant watt is 331 lumensper radiant watt. The efficacy is 91 lumens per watt.

FIG. 17 shows a power spectral distribution of an LED lamp in aphase-shift configuration, in accordance with another embodimentpresented. The phase-shift configuration shown in FIG. 18 is produced byan array of LED dies in the 3:3:2:3 ratio, driven as follows: (1) threemint LEDs driven parallel at 11.27V, 988 mA, 1.679 radiant watts; (2)two red-orange LEDs driven at 3.78V, 180 mA, 1.971 radiant, and (3)three blue LEDs driven at 9.07V, 296 mA, 0.8719 radiant watts. Thedominant wavelength is 476.9 nm. The general CRI is 88. The colortemperature is 6235 K. The luminous power per radiant watt is 298 lumensper radiant watt. The efficacy is 63 lumens per watt.

FIG. 18 shows a power spectral distribution of an LED lamp in a generallighting configuration, in accordance with another embodiment presented.The general lighting configuration shown in FIG. 19 is produced by anarray of LED dies in the 3:3:2:3 ratio, driven as follows: (1) threecyan LEDs driven at 8.16V, 218 mA, to generate 0.4332 radiant watts; (2)three mint LEDs driven parallel at 11.23V, 972 mA, 1.869 radiant watts;(3) two red-orange LEDs driven at 3.89V, 295 mA, 0.3520 radiant watts.The dominant wavelength is 565.6 nm. The general CRI is 90. The colortemperature is 4828 K. The luminous power per radiant watt is 335 lumensper radiant watt. The efficacy is 68 lumens per watt

In another embodiment, there is provided a tunable LED lamp forproducing a biologically-adjusted light output with a color renderingindex above 70. The LED lamp comprises: a base; a housing attached tothe base; a power circuit disposed within the housing and havingelectrical leads attached to the base; a driver circuit disposed withinthe housing and electrically coupled to the power circuit; and a heatsink disposed about the housing. The LED lamp further comprises: aplurality of LED dies mounted on a support coupled to the housing,wherein each of the plurality of LED dies is electrically coupled to anddriven by the driver circuit. The plurality of LED dies includes two redLED dies, three cyan LED dies, four mint LED dies, and three blue LEDdies. The LED lamp further comprises: an output-select controllerelectrically coupled to the driver circuit to program the driver circuitto drive the LED dies in one of a plurality of light outputconfigurations. The plurality of light output configurations includes apre-sleep configuration, a phase-shift configuration, and a generallighting configuration.

The output-select controller may include a user-input interface allowinga user to select the light output configuration. The LED lamp my furtherinclude an input sensor electrically coupled to the output-selectcontroller to provide an input variable for consideration in theselection of the light output configuration. The input sensor may be athermal sensor, a photo-sensor, and/or a GPS chip. The input variablemay be selected from the group consisting of: an ambient temperature, asupport temperature, an LED die temperature, a housing temperature, thelight output produced by the lamp, an ambient light, a daily lightcycle, a location of the lamp, an expected ambient light, a seasonallight cycle variation, a time of day, and any combinations and/orequivalents thereof.

In the pre-sleep configuration, the driver circuit drives the pluralityof LED dies such that a blue output intensity level, in a visiblespectral output range of between about 380 nm and about 485 nm, is lessthan about 10% of a relative spectral power of any other peaks in thevisible spectral output above about 485 nm. For example, the drivercircuit may drive the plurality of LED dies such that about 150 mA ofcurrent is delivered to the mint LED dies; about 360 mA of current isdelivered to the red LED dies; and about 40 mA of current is deliveredto the cyan LED dies.

In the phase-shift configuration, the driver circuit drives theplurality of LED dies such that a blue output intensity level, in avisible spectral output range of between about 455 nm and about 485 nm,is greater than about 125% of a relative spectral power of any otherpeaks in the visible spectral output above about 485 nm. The colorrendering index in the phase-shift configuration may be greater than 80.For example, the driver circuit may drive the plurality of LED dies suchthat about 510 mA of current is delivered to the mint LED dies; about1800 mA of current is delivered to the red LED dies; about 40 mA ofcurrent is delivered to the cyan LED dies; and about 100 mA of currentis delivered to the blue LED dies.

In the general lighting configuration, the driver circuit drives theplurality of LED dies such that a blue output intensity level, in avisible spectral output range of between about 380 nm and about 485 nm,is between about 100% to about 20% of a relative spectral power of anyother peaks in the visible spectral output above about 485 nm. The colorrendering index in the general lighting configuration may be greaterthan 85. For example, the driver circuit may drive the plurality of LEDdies such that about 450 mA of current is delivered to the mint LEDdies; about 230 mA of current is delivered to the red LED dies; about110 mA of current is delivered to the cyan LED dies; and about 60 mA ofcurrent is delivered to the blue LED dies.

In another embodiment, there is provided an LED lamp, comprising: ahousing; a driver circuit disposed within the housing and configured toelectrically couple to a power source; and a plurality of LED diesmounted on a support coupled to the housing, wherein each of theplurality of LED dies is electrically coupled to and driven by thedriver circuit. The LED lamp further includes an output-selectcontroller electrically coupled to the driver circuit to program thedriver circuit to drive the LED dies in one of a plurality of lightoutput configurations. The output-select controller may also include auser-input interface allowing a user to select the light outputconfiguration.

The plurality of light output configurations includes a pre-sleepconfiguration and a general lighting configuration. The plurality oflight output configurations may further include a phase-shiftconfiguration. The plurality of LED dies may include red LED dies, cyanLED dies, mint LED dies, and blue LED dies. The ratio of red LED dies tocyan LED dies to mint LED dies to blue LED dies of 2:3:4:3,respectively. The LED lamp may be tunable to produce abiologically-adjusted light output with a color rendering index above70.

The LED lamp may further comprise an input sensor electrically coupledto the output-select controller to provide an input variable forconsideration in the selection of the light output configuration. Theinput sensor may be a thermal sensor, a photo-sensor, and/or a GPS chip.The input variable may be selected from the group consisting of: anambient temperature, a support temperature, an LED die temperature, ahousing temperature, the light output produced by the lamp, an ambientlight, a daily light cycle, a location of the lamp, an expected ambientlight, a seasonal light cycle variation, a time of day, and anycombinations and/or equivalents thereof.

In the pre-sleep configuration, the driver circuit drives the pluralityof LED dies such that a blue output intensity level, in a visiblespectral output range of between about 380 nm and about 485 nm, is lessthan about 10% of a relative spectral power of any other peaks in thevisible spectral output above about 485 nm. For example, the drivercircuit may drive the plurality of LED dies such that about 150 mA ofcurrent is delivered to the mint LED dies; about 360 mA of current isdelivered to the red LED dies; and about 40 mA of current is deliveredto the cyan LED dies.

In the phase-shift configuration, the driver circuit drives theplurality of LED dies such that a blue output intensity level, in avisible spectral output range of between about 455 nm and about 485 nm,is greater than about 125% (or greater than about 150%; or greater thanabout 200%) of a relative spectral power of any other peaks in thevisible spectral output above about 485 nm. The color rendering index inthe phase-shift configuration may be greater than 80. For example, thedriver circuit may drive the plurality of LED dies such that about 510mA of current is delivered to the mint LED dies; about 180 mA of currentis delivered to the red LED dies; about 40 mA of current is delivered tothe cyan LED dies; and about 100 mA of current is delivered to the blueLED dies

In the general lighting configuration, the driver circuit drives theplurality of LED dies such that a blue output intensity level, in avisible spectral output range of between about 380 nm and about 485 nm,is between about 100% to about 20% of a relative spectral power of anyother peaks in the visible spectral output above about 485 nm. The colorrendering index in the general lighting configuration may be greaterthan 85. For example, the driver circuit may drive the plurality of LEDdies such that about 450 mA of current is delivered to the mint LEDdies; about 230 mA of current is delivered to the red LED dies; about110 mA of current is delivered to the cyan LED dies; and about 60 mA ofcurrent is delivered to the blue LED dies.

In another embodiment, there is provided a tunable LED lamp forproducing a biologically-adjusted light output with a color renderingindex above 70, comprising: a base; a housing attached to the base; apower circuit disposed within the housing and having electrical leadsattached to the base; a driver circuit disposed within the housing andelectrically coupled to the power circuit; a heat sink disposed aboutthe housing; a plurality of LED dies mounted on a support coupled to thehousing, wherein each of the plurality of LED dies is electricallycoupled to and driven by the driver circuit, and wherein the pluralityof LED dies includes a ratio of two red-orange LED dies to three cyanLED dies to three mint LED dies to one blue LED dies; and anoutput-select controller electrically coupled to the driver circuit toprogram the driver circuit to drive the LED dies in one of a pluralityof light output configurations, wherein the plurality of light outputconfigurations includes a pre-sleep configuration, a phase-shiftconfiguration, and a general lighting configuration. In the pre-sleepconfiguration, the driver circuit may drive the plurality of LED diessuch that about 950 mA of current is delivered to the mint LED dies,about 1,000 mA of current is delivered to the red-orange LED dies, about65 mA of current is delivered to the cyan LED dies; and about 30 mA ofcurrent is delivered to the blue LED dies. In the phase-shiftconfiguration, the driver circuit may drive the plurality of LED diessuch that about 950 mA of current is delivered to the mint LED dies,about 150 mA of current is delivered to the red-orange LED dies, about235 mA of current is delivered to the cyan LED dies, and about 525 mA ofcurrent is delivered to the blue LED dies. In the general lightingconfiguration, the driver circuit may drive the plurality of LED diessuch that about 500 mA of current is delivered to the mint LED dies,about 250 mA of current is delivered to the red-orange LED dies, about210 mA of current is delivered to the cyan LED dies, and about 190 mA ofcurrent is delivered to the blue LED dies. In other embodiments,alternative currents may be delivered to vary the radiant fluxes andachieve the desired spectral output.

In yet another embodiment, there is provided a method of manufacturing atunable LED lamp for producing a biologically-adjusted light output witha color rendering index above 70. The method comprises: (a) attaching abase to a housing; (b) electrically coupling leads of a power circuitwithin the housing to the base; (c) electrically coupling a drivercircuit disposed within the housing to the power circuit; (d) mounting aplurality of LED dies on a support coupled to the housing such that eachof the plurality of LED dies is electrically coupled to and driven bythe driver circuit, and wherein the plurality of LED dies includes twored LED dies, three cyan LED dies, four mint LED dies, and three blueLED dies; and (e) configuring the driver circuit to drive the LED diesin one of a plurality of light output configurations, wherein theplurality of light output configurations includes a pre-sleepconfiguration, a phase-shift configuration, and a general lightingconfiguration.

The method may further comprise: (f) configuring the driver circuit todrive the plurality of LED dies such that a blue output intensity level,in a visible spectral output range of between about 380 nm and about 485nm, is less than about 10% of a relative spectral power of any otherpeaks in the visible spectral output above about 485 nm; (g) configuringthe driver circuit to drive the plurality of LED dies such that a blueoutput intensity level, in a visible spectral output range of betweenabout 455 nm and about 485 nm, is greater than about 125% of a relativespectral power of any other peaks in the visible spectral output aboveabout 485 nm; and/or (h) configuring the driver circuit to drive theplurality of LED dies such that a blue output intensity level, in avisible spectral output range of between about 380 nm and about 485 nm,is between about 100% to about 20% of a relative spectral power of anyother peaks in the visible spectral output above about 485 nm.

The method may further comprise: (i) configuring the driver circuit todrive the plurality of LED dies such that about 150 mA of current isdelivered to the mint LED dies, about 360 mA of current is delivered tothe red LED dies, and about 40 mA of current is delivered to the cyanLED dies; (j) configuring the driver circuit to drive the plurality ofLED dies such that about 510 mA of current is delivered to the mint LEDdies, about 180 mA of current is delivered to the red LED dies, about 40mA of current is delivered to the cyan LED dies, and about 100 mA ofcurrent is delivered to the blue LED dies; and/or (k) configuring thedriver circuit to drive the plurality of LED dies such that about 450 mAof current is delivered to the mint LED dies, about 230 mA of current isdelivered to the red LED dies, about 110 mA of current is delivered tothe cyan LED dies, and about 60 mA of current is delivered to the blueLED dies.

In another embodiment, there is provided an LED lamp comprising ahousing, a driver circuit disposed within the housing and configured toelectrically couple to a power source, and a plurality of LED diesmounted on a support coupled to the housing. Each of the plurality ofLED dies may be electrically coupled to and driven by the drivercircuit; and an output-select controller electrically coupled to thedriver circuit to program the driver circuit to drive the LED dies inone of a plurality of light output configurations, wherein the pluralityof light output configurations includes a pre-sleep configuration and ageneral lighting configuration. The plurality of LED dies includesred-orange LED dies, cyan LED dies, mint LED dies, and blue LED dies.The plurality of LED dies includes a ratio of red-orange LED dies tocyan LED dies to mint LED dies to blue LED dies of 2:3:3:1,respectively.

In another embodiment, there is provided a method of manufacturing atunable LED lamp for producing a biologically-adjusted light output witha color rendering index above 70, comprising: attaching a base to ahousing; electrically coupling leads of a power circuit within thehousing to the base; electrically coupling a driver circuit disposedwithin the housing to the power circuit; mounting a plurality of LEDdies on a support coupled to the housing such that each of the pluralityof LED dies is electrically coupled to and driven by the driver circuit,and wherein the plurality of LED dies includes two red-orange LED dies,three cyan LED dies, three mint LED dies, and one blue LED dies; andconfiguring the driver circuit to drive the LED dies in one of aplurality of light output configurations, wherein the plurality of lightoutput configurations includes a pre-sleep configuration, a phase-shiftconfiguration, and a general lighting configuration. In the pre-sleepconfiguration the method may further comprises configuring the drivercircuit to drive the plurality of LED dies such that about 950 mA ofcurrent is delivered to the mint LED dies, about 1,000 mA of current isdelivered to the red-orange LED dies, about 65 mA of current isdelivered to the cyan LED dies, and about 30 mA of current is deliveredto the blue LED dies. In the phase-shift configuration the method mayfurther comprise: configuring the driver circuit to drive the pluralityof LED dies such that about 950 mA of current is delivered to the mintLED dies, about 150 mA of current is delivered to the red LED dies,about 235 mA of current is delivered to the cyan LED dies, and about 525mA of current is delivered to the blue LED dies. In the general lightingconfiguration the method may further comprise: configuring the drivercircuit to drive the plurality of LED dies such that about 500 mA ofcurrent is delivered to the mint LED dies, about 250 mA of current isdelivered to the red LED dies, about 210 mA of current is delivered tothe cyan LED dies, and about 190 mA of current is delivered to the blueLED dies.

It will be evident to those skilled in the art, that other dieconfiguration or current schemes may be employed to achieve the desiredspectral output of the LED lamp for producing biologically adjustedlight.

In another embodiment, there is provided an LED lamp comprising ahousing, a driver circuit disposed within the housing and configured toelectrically couple to a power source, and a plurality of LED diesmounted on a support coupled to the housing. Each of the plurality ofLED dies may be electrically coupled to and driven by the drivercircuit. The plurality of LED dies may include mint LED dies, hyper redLED dies, and blue LED dies. In some embodiments, the plurality of LEDdies includes a ratio of mint LED dies to hyper red LED dies to blue LEDdies of 15:5:4, respectively.

In some embodiments, all of the plurality of LED dies may be seriallyconnected. Furthermore, the drive circuit may be configured to operatethe plurality of LED dies such that a relative peak intensity of lightemitted by the blue LED dies is within the range from 90% to 100% of apeak intensity of light emitted by the hyper red LED dies and a relativepeak intensity of light emitted by the mint LED dies is within the rangefrom 50% to 60% of the peak intensity of light emitted by the hyper redLED dies.

Additionally, the drive circuit may be configured to operate theplurality of LED dies to emit light having a color temperature of atleast 6,200 K. More specifically, the drive circuit may be configured tooperate the plurality of LED dies to emit light having a colortemperature of 6,240 K.

Additionally, the drive circuit may be configured to operate theplurality of LED dies to emit light having a color rendering index of atleast 90. More specifically, the drive circuit may be configured tooperate the LED dies to have a color rendering index of 92.2.

In another embodiment, there is provided an LED lamp comprising ahousing, a driver circuit disposed within the housing and configured toelectrically couple to a power source, and a plurality of LED diesmounted on a support coupled to the housing. Each of the plurality ofLED dies may be electrically coupled to and driven by the drivercircuit. The plurality of LED dies may include mint LED dies, hyper redLED dies, and blue LED dies. In some embodiments, the plurality of LEDdies includes a ratio of mint LED dies to hyper red LED dies to blue LEDdies of 1:1:1, respectively. Furthermore, the plurality of LED dies maycomprise 7 mint LED dies, 7 hyper red LED dies, and 7 blue LED dies.

In some embodiments, each of the like-colored LED dies may be seriallyconnected. That is to say, the mint LED dies may be serially connected,the hyper red LED dies may be serially connected, and the blue LED diesmay be serially connected. Furthermore, the drive circuit may beconfigured to direct power to the various serially-connected LED diesunequally. In some embodiments, the driver circuit may deliver power tothe plurality of LED dies in a ratio of 6.9 watts to the mint LED dies,3.2 watts to the hyper red LED dies, and 2.0 watts to the blue LED dies.

In some embodiments, the drive circuit may be configured to operate theplurality of LED dies such that a relative peak intensity of lightemitted by the blue LED dies is within the range from 80% to 90% of apeak intensity of light emitted by the hyper red LED dies and a relativepeak intensity of light emitted by the mint LED is within the range from30% to 40% of the peak intensity of light emitted by the hyper red LEDdies.

Additionally, the drive circuit may be configured to operate theplurality of LED dies to emit light having a color temperature of atleast 6,200 K. More specifically, the drive circuit may be configured tooperate the plurality of LED dies to emit light having a colortemperature of 6,202 K.

Additionally, the drive circuit may be configured to operate theplurality of LED dies to emit light having a color rendering index of atleast 90. More specifically, the drive circuit may be configured tooperate the LED dies to have a color rendering index of 91.3.

Referring now to FIG. 19, an additional embodiment of the invention ispresented. FIG. 19 presents a plotting 1900 of the scaled spectral powerdistribution of a lighting device according to an embodiment of theinvention. In some embodiments, the lighting device may be structurallysimilar to the luminaire presented in either FIGS. 2-7 and/or FIG. 15,or may be a troffer lighting fixture, such as those presented in U.S.patent application Ser. No. 14/853,516 titled Illumination and GrowLight System and Associated Methods, U.S. Design Pat. No. D744,689titled Troffer Luminaire, and U.S. Design Pat. No. D738,032 titledSquare Troffer Luminaire, the contents of each of which are incorporatedherein by reference except to the extent disclosure therein isinconsistent with disclosure herein.

The LED packages of the present embodiment may be populated by, and insome embodiments consist of, at least one LED operable to emit lighthaving a peak wavelength within the range from about 450 nm to about 455nm, including a peak intensity of about 450 nm, defined as a blue LED,and at least one LED operable to emit light having a peak intensitywithin the range from about 475 nm to about 495 nm, defined as a cyanLED. In some embodiments, the cyan LED may emit light having a peakintensity within the range from about 480 nm to about 490 nm. In someembodiments, the cyan LED may have a peak intensity within the rangefrom about 480 nm to about 495 nm. The LED packages may exclude LEDsoperable to emit light above 500 nm or, alternatively, above 600 nm. Insome embodiments, there may be a plurality of LED packages, eachconsisting of LEDs configured to emit light having the same spectralpower distribution. Furthermore, a first LED package of the plurality ofLED packages may emit light having a first color, and a second LEDpackage may emit light having a second color that is different from thefirst. For example, the first LED package may comprise blue LEDs and thesecond LED package may comprise cyan LEDs. Furthermore, the first LEDpackage may comprise a color conversion layer, as described hereinbelow.

The LED packages may have a ratio of blue LEDs to cyan LEDs within therange from 1:3 to 3:1. In some embodiments, the ratio of blue LEDs tocyan LEDs may be approximately 1:1.

Furthermore, the LED packages may comprise a color conversion layeroperable to absorb light emitted by the blue LED and emit light having apeak wavelength within the range from about 580 nm to about 630 nm,specifically having a peak within the range from about 590 nm to about595 nm. The color conversion layer may perform a Stokes shift on lightwithin the range from about 440 nm to about 460 nm. Moreover, the colorconversion layer may be operable to emit light excluding an intensitypeak above 600 nm. In some embodiments, the color conversion layer maybe applied to the blue LED. Advantageously, the present embodiment mayrequire no more than a single phosphor material to result in a spectrumas described hereinbelow.

The lighting device may be operable to emit light have lightingcharacteristics including a CRI of at least 90, and a CRI #9 strong redvalue of at least 40. In some embodiments, the device may emit lighthaving a CRI #9 strong red value of at least 50. In some embodiments,the device may emit light having a CRI #9 strong red value of at least90. Furthermore, the lighting device may be operable to emit lighthaving a CCT of less than 6,000 K. In some embodiments, the lightingdevice may be operable to emit light having a CCT within the range fromabout 4,900 K to about 5,100 K. In some embodiments, the lighting devicemay be operable to emit light having a CCT that is less than 5,000 K. Insome embodiments, the lighting device may be operable to emit lighthaving a CCT within the range from about 3,900 K to about 4,100 K. Insome embodiments, the lighting device may be operable to emit lighthaving a CCT that is less than 4,000 K.

Additionally, the lighting device may be operable to emit light having atrough in its spectral power distribution within the range from about450 nm to about 475 nm. In some embodiments, the trough may be centeredwithin the range from about 460 nm to about 470 nm.

In an alternative embodiment, the lighting device may comprise aplurality of LED packages comprising at least one blue LED, at least onecyan LED, and at least one red LED. Furthermore, in such embodiments,the LED packages may comprise a phosphor as described in the previousembodiment. In some embodiments, the LED packages may have a ratio ofblue LEDs to cyan LEDs to red LEDs of 10:3:1. Additionally, the CRI forsuch embodiments may be approximately 94.

In each of the embodiments described hereinabove, it is furthercontemplated that the pluralities of LEDs may be fabricated as achip-on-board (“COB”) package. For example, where the lighting devicecomprises cyan and blue LEDs, each of the cyan and blue LEDs may befabricated and comprised by a single COB package, and one or more COBpackages may be comprised by the lighting device. Furthermore, the COBpackage may comprise a color conversion material as describedhereinabove. For example, where a potting compound is used in theprocess of attaching the LED COB package to an LED board, the pottingcompound may be generally transparent or translucent, and may comprise acolor conversion material.

CONCLUSION

The foregoing description of the invention has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed.Other modifications and variations may be possible in light of the aboveteachings. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical application,and to thereby enable others skilled in the art to best utilize theinvention in various embodiments and various modifications as are suitedto the particular use contemplated. It is intended that the appendedclaims be construed to include other alternative embodiment of theinvention; including equivalent structures, components, methods, andmeans.

It is to be appreciated that the Detailed Description section, and notthe Summary and Abstract sections, is intended to be used to interpretthe claims. The Summary and Abstract sections may set forth one or more,but not all exemplary embodiments of the present invention ascontemplated by the inventor(s), and thus, are not intended to limit thepresent invention and the appended claims in any way.

That which is claimed is:
 1. An LED lamp comprising: a housing; a drivecircuit configured to electrically couple to a power source; and an LEDpackage that is electrically coupled to and driven by the drive circuit,the LED package comprising: a first LED configured to emit light havinga peak intensity of about 450 nm, a second LED configured to emit lighthaving a peak intensity within the range from 475 nm to 495 nm, and acolor conversion material configured to perform a Stokes shift on lighthaving a wavelength within the range from 440 nm to 460 nm.
 2. The LEDlamp according to claim 1 wherein light emitted by the LED lamp isconfigured to emit light that suppresses melatonin secretion in anobserver.
 3. The LED lamp according to claim 1 wherein the LED lamp doesnot comprise an LED configured to emit light having a peak intensity ata wavelength greater than 600 nm.
 4. The LED lamp according to claim 1wherein the LED lamp does not comprise a color conversion materialconfigured to emit light having a peak intensity at a wavelength greaterthan 600 nm.
 5. The LED lamp according to claim 1 wherein the LEDpackage consists of: a first LED configured to emit light having a peakintensity of about 450 nm; a second LED configured to emit light havinga peak intensity within the range from 475 nm to 495 nm; and a colorconversion material configured to perform a Stokes shift on light havinga wavelength within the range from 440 nm to 460 nm.
 6. The LED lampaccording to claim 1 comprising a plurality of LED packages.
 7. The LEDlamp according to claim 6 wherein the plurality of LED packages consistsof LED packages comprising: a first LED configured to emit light havinga peak intensity of about 450 nm; a second LED configured to emit lighthaving a peak intensity within the range from 475 nm to 495 nm; and acolor conversion material configured to perform a Stokes shift on lighthaving a wavelength within the range from 440 nm to 460 nm.
 8. The LEDlamp according to claim 6 wherein the plurality of LED packages consistsof LED packages consisting of: a first LED configured to emit lighthaving a peak intensity of about 450 nm; a second LED configured to emitlight having a peak intensity within the range from 475 nm to 495 nm;and a color conversion material configured to perform a Stokes shift onlight having a wavelength within the range from 440 nm to 460 nm.
 9. TheLED lamp according to claim 1 wherein light emitted by the LED lamp hasa CRI of at least
 90. 10. The LED lamp according to claim 1 whereinlight emitted by the LED lamp has a CCT of less than 5000K.
 11. The LEDlamp according to claim 1 wherein light emitted by the LED lamp has aCRI #9 value of at least
 40. 12. The LED lamp according to claim 11wherein light emitted by the LED lamp has a CCT of less than 4000K. 13.The LED lamp according to claim 1 wherein the color conversion materialis configured to emit light having a peak intensity within the rangefrom 500 nm to 599 nm.
 14. The LED lamp according to claim 1 wherein thesecond LED configured to emit light having a peak intensity within therange from 480 nm to 490 nm.
 15. The LED lamp according to claim 1wherein the housing is configured to facilitate the attachment of theLED lamp to a troffer light fixture.
 16. The LED lamp according to claim1 further comprising an output select controller electrically coupled tothe drive circuit to program the drive circuit to drive the LED packagein one of a plurality of light output configurations, wherein theplurality of light output configurations includes a general lightingconfiguration and a phase-shift configuration.
 17. The LED lampaccording to claim 1 wherein light output in the phase-shiftconfiguration has a peak intensity within the range from 475 nm to 490nm that is greater than a peak intensity within the range from 475 nm to490 nm of the light output in the general lighting configuration
 18. AnLED lamp comprising: a housing; a drive circuit configured toelectrically couple to a power source; and a plurality of LED packagesthat are electrically coupled to and driven by the drive circuit, eachLED package of the plurality of LED packages comprising: a first LEDconfigured to emit light having a peak intensity of about 450 nm, asecond LED configured to emit light having a peak intensity within therange from 475 nm to 495 nm, and a color conversion material configuredto perform a Stokes shift on light having a wavelength within the rangefrom 440 nm to 460 nm; wherein the LED lamp does not comprise an LED ora color conversion material configured to emit light having a wavelengthgreater than 600 nm; and wherein light emitted by the LED lamp has a CRIof at least
 90. 19. The LED lamp according to claim 18 wherein lightemitted by the LED lamp has a CCT of less than 5000K and a CRI #9 valueof at least
 40. 20. An LED lamp comprising: a housing; a drive circuitconfigured to electrically couple to a power source; and an LED packagethat is electrically coupled to and driven by the drive circuit, the LEDpackage consisting of: a first LED configured to emit light having apeak intensity of about 450 nm, a second LED configured to emit lighthaving a peak intensity within the range from 475 nm to 490 nm, and acolor conversion material configured to perform a Stokes shift on lighthaving a wavelength within the range from 440 nm to 460 nm; whereinlight emitted by the LED lamp has a CRI of at least 90, a CRI #9 valueof at least 40, and a CCT of less than 4000K.